[Objective] The aim was to select a cultivation method suitable for sandy lands in Liaoning Province. [Method] The research explored effects of autumn plowing, autumn rotary cultivation, autumn ridging, and rotary cul...[Objective] The aim was to select a cultivation method suitable for sandy lands in Liaoning Province. [Method] The research explored effects of autumn plowing, autumn rotary cultivation, autumn ridging, and rotary cultivation before spring sowing on physical and chemical properties. [Result] By autumn plowing, surface soils were seriously eroded, more water was evaporated, and more nutrients lost; by autumn rotary cultivation, surface soils were seriously eroded also, reducing wa- ter content and nutrients; by autumn ridging, surface soils were slightly eroded, so that evaporation was light and fewer nutrients lost; by rotary cultivation before spring sowing, soil erosion was the lightest, with more water and nutrients maintained. [Conclusion] It is effective for improving anti-wind erosion by no-tillage during fallow period and land reclamation before sowing in semi-dry areas.展开更多
Considering passenger trains'key role in remote regions,this study employed machine vision technology to monitor five posture parameters of the second car of a conventional passenger train,aiming to investigate th...Considering passenger trains'key role in remote regions,this study employed machine vision technology to monitor five posture parameters of the second car of a conventional passenger train,aiming to investigate the influence of windbreaks and crosswinds along railways on the operating postures of conventional passenger trains.The study found that when passing through the anti-wind tunnel with holes,the amplitudes of posture parameters were smaller than those of other windbreaks,demonstrating the superior performance of this windbreak in maintaining posture stability compared to others.In tunnel sections,larger amplitudes of these parameters were observed for the tail car than the head car,while the opposite occurred in non-tunnel sections.Notably,during tunnel transit,their amplitudes did not increase monotonically with speed but peaked at a specific speed that most adversely affected the operating posture.These conclusions have a great significance for improving operating safety under crosswinds.展开更多
以带运动抑制结构的圆筒型浮式生产储卸油装置(Cylindrical Floating Production Storage and Offloading,CFPSO)为研究对象,在低速风洞中对CFPSO流载荷进行测量。为获得均匀流并减少边界层的影响,采用距离地面一定高度的小地板。热线...以带运动抑制结构的圆筒型浮式生产储卸油装置(Cylindrical Floating Production Storage and Offloading,CFPSO)为研究对象,在低速风洞中对CFPSO流载荷进行测量。为获得均匀流并减少边界层的影响,采用距离地面一定高度的小地板。热线测量结果表明,采用小地板能够获得更均匀的流剖面。通过风洞试验对4种不同型式的运动抑制结构流载荷进行测量,进一步采用数值模拟方法对不同型式运动抑制结构的尾流场进行分析。结果表明:运动抑制结构通过对尾涡的限制,减少能量损耗,实现减阻效果。研究结果可为运动抑制结构的设计提供一定的参考。展开更多
文摘[Objective] The aim was to select a cultivation method suitable for sandy lands in Liaoning Province. [Method] The research explored effects of autumn plowing, autumn rotary cultivation, autumn ridging, and rotary cultivation before spring sowing on physical and chemical properties. [Result] By autumn plowing, surface soils were seriously eroded, more water was evaporated, and more nutrients lost; by autumn rotary cultivation, surface soils were seriously eroded also, reducing wa- ter content and nutrients; by autumn ridging, surface soils were slightly eroded, so that evaporation was light and fewer nutrients lost; by rotary cultivation before spring sowing, soil erosion was the lightest, with more water and nutrients maintained. [Conclusion] It is effective for improving anti-wind erosion by no-tillage during fallow period and land reclamation before sowing in semi-dry areas.
基金Projects(52302447,52388102)supported by the National Natural Science Foundation of China。
文摘Considering passenger trains'key role in remote regions,this study employed machine vision technology to monitor five posture parameters of the second car of a conventional passenger train,aiming to investigate the influence of windbreaks and crosswinds along railways on the operating postures of conventional passenger trains.The study found that when passing through the anti-wind tunnel with holes,the amplitudes of posture parameters were smaller than those of other windbreaks,demonstrating the superior performance of this windbreak in maintaining posture stability compared to others.In tunnel sections,larger amplitudes of these parameters were observed for the tail car than the head car,while the opposite occurred in non-tunnel sections.Notably,during tunnel transit,their amplitudes did not increase monotonically with speed but peaked at a specific speed that most adversely affected the operating posture.These conclusions have a great significance for improving operating safety under crosswinds.
文摘以带运动抑制结构的圆筒型浮式生产储卸油装置(Cylindrical Floating Production Storage and Offloading,CFPSO)为研究对象,在低速风洞中对CFPSO流载荷进行测量。为获得均匀流并减少边界层的影响,采用距离地面一定高度的小地板。热线测量结果表明,采用小地板能够获得更均匀的流剖面。通过风洞试验对4种不同型式的运动抑制结构流载荷进行测量,进一步采用数值模拟方法对不同型式运动抑制结构的尾流场进行分析。结果表明:运动抑制结构通过对尾涡的限制,减少能量损耗,实现减阻效果。研究结果可为运动抑制结构的设计提供一定的参考。
