The effects of mechanical activation in a planetary mill on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation railings generated by wet magnetic separa...The effects of mechanical activation in a planetary mill on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation railings generated by wet magnetic separation process were studied using X-ray and laser diffraction methods. The results revealed the relationship between variations in the mean particle size of activated powders and the milling time. The crystallite size, microstrain, lattice parameters and unit cell volumes were determined for different milling times in powder samples of quartz, hematite, dolomite, and magnetite from the beneficiation tailings. The main trends in the variation of the crystallite size of quartz, hematite, dolomite, and magnetite as a function mean particle size of powder samples were revealed. Changes in the particle shape as a function of the activation time was also investigated.展开更多
In order to distinguish the filling effect and volcanic activity and explore the ways motivating the activity of rich-silicon iron ore tailing(IOT), inert quartz was brought in as the correction standard, the influe...In order to distinguish the filling effect and volcanic activity and explore the ways motivating the activity of rich-silicon iron ore tailing(IOT), inert quartz was brought in as the correction standard, the influences of fineness, calcination, thermal curing system and some other factors were investigated by IR, XRD, MIP, and so on microscopic methods. The experimental results show grinding and calcination can only change the amorphous state of SiO2, and IOT do not have volcanic activity in concrete cured under room temperature condition. Thermal curing systems can stimulate the activity of IOT, especially mortar cured by autoclave curing system can consume a large amount of Ca(OH)2 and hard calcium silicate and has a closer structure. When the specific surface area of IOT powder is 800 m^2/kg, and 30% cement is replaced by IOT powder, the mortar strength with IOT powder is even higher than that with cementonly.展开更多
Lizards use the synergy between their feet and tail to climb on slopes and vertical terrains.They use their soft adhesive feet with millions of small hairs to increase their contact area with the terrain surface and p...Lizards use the synergy between their feet and tail to climb on slopes and vertical terrains.They use their soft adhesive feet with millions of small hairs to increase their contact area with the terrain surface and press their tails against the terrain to actively maintain stability during climbing.Inspired by this,we propose a bio-inspired climbing robot based on a new approach wherein the synergy between soft feet and an active tail with a soft adhesive tip allows the robot to climb stably on even and uneven terrains at different slope angles.We evaluate and compare the climbing performance of the robot on three different terrains(hard,soft,and fluffy)at different slope angles.Various robot configurations are employed,including those with standard hard feet and soft feet in combination with an active tail-with and without a soft tip.The experimental results show that the robot having soft feet and a tail with the soft tip achieves the best climbing performance on all terrains,with maximum climbing slopes of 40°,45°,and 50°on fluffy,soft,and hard terrains,respectively.Its payload capacity depends on the type of terrain and the inclination angle.Moreover,our robot performs multi-terrain transitions(climbing from horizontal to sloped terrains)on three different terrains of a slope.This approach can allow a climbing robot to walk and climb on different terrains,extending the operational range of the robot to areas with complex terrains and slopes,e.g.,in inspection,exploration,and construction.展开更多
文摘The effects of mechanical activation in a planetary mill on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation railings generated by wet magnetic separation process were studied using X-ray and laser diffraction methods. The results revealed the relationship between variations in the mean particle size of activated powders and the milling time. The crystallite size, microstrain, lattice parameters and unit cell volumes were determined for different milling times in powder samples of quartz, hematite, dolomite, and magnetite from the beneficiation tailings. The main trends in the variation of the crystallite size of quartz, hematite, dolomite, and magnetite as a function mean particle size of powder samples were revealed. Changes in the particle shape as a function of the activation time was also investigated.
基金Funded by the National Natural Science Foundation of China(51372185)
文摘In order to distinguish the filling effect and volcanic activity and explore the ways motivating the activity of rich-silicon iron ore tailing(IOT), inert quartz was brought in as the correction standard, the influences of fineness, calcination, thermal curing system and some other factors were investigated by IR, XRD, MIP, and so on microscopic methods. The experimental results show grinding and calcination can only change the amorphous state of SiO2, and IOT do not have volcanic activity in concrete cured under room temperature condition. Thermal curing systems can stimulate the activity of IOT, especially mortar cured by autoclave curing system can consume a large amount of Ca(OH)2 and hard calcium silicate and has a closer structure. When the specific surface area of IOT powder is 800 m^2/kg, and 30% cement is replaced by IOT powder, the mortar strength with IOT powder is even higher than that with cementonly.
基金supported by the National Key R&D Program of China,Topic 4-NUAA(Grant No.2020 YFB1313504)to PM.
文摘Lizards use the synergy between their feet and tail to climb on slopes and vertical terrains.They use their soft adhesive feet with millions of small hairs to increase their contact area with the terrain surface and press their tails against the terrain to actively maintain stability during climbing.Inspired by this,we propose a bio-inspired climbing robot based on a new approach wherein the synergy between soft feet and an active tail with a soft adhesive tip allows the robot to climb stably on even and uneven terrains at different slope angles.We evaluate and compare the climbing performance of the robot on three different terrains(hard,soft,and fluffy)at different slope angles.Various robot configurations are employed,including those with standard hard feet and soft feet in combination with an active tail-with and without a soft tip.The experimental results show that the robot having soft feet and a tail with the soft tip achieves the best climbing performance on all terrains,with maximum climbing slopes of 40°,45°,and 50°on fluffy,soft,and hard terrains,respectively.Its payload capacity depends on the type of terrain and the inclination angle.Moreover,our robot performs multi-terrain transitions(climbing from horizontal to sloped terrains)on three different terrains of a slope.This approach can allow a climbing robot to walk and climb on different terrains,extending the operational range of the robot to areas with complex terrains and slopes,e.g.,in inspection,exploration,and construction.