A conveyor linear system assumption is based on an approximate description of belt mechanics behavior and constant elastic moduli. It produces analysis errors and improper dynamics simulation in large conveyors. The b...A conveyor linear system assumption is based on an approximate description of belt mechanics behavior and constant elastic moduli. It produces analysis errors and improper dynamics simulation in large conveyors. The belt non-linear characteristics based on sag are described and the belt equivalent elastic moduli expression is deduced. The relationship between belt-equivalent elastic module and elastic module is studied, and their ratio varies from 0.1 to 1.0. The non-linear motion equation with a lumped element model is put forward. Its increment equation and numerical solution are built. A dynamics simulation on a conveyor is carried out, mainly to calculate and compare belt speed, acceleration, tension, displacement of gravity take-up and wave period with linear and non-linear models. It shows that the simulation errors between two models vary from 6% to 50%.展开更多
We investigated the influences of liquid water transfer property of cotton fabric on human physiological responses, such as ear canal temperature, heart rate, blood pressure, stress hormone, during exercise and recove...We investigated the influences of liquid water transfer property of cotton fabric on human physiological responses, such as ear canal temperature, heart rate, blood pressure, stress hormone, during exercise and recovery. Long sleeves cotton knitted sportswear treated to have special liquid water transfer property were prepared: (1) Hydrophilic; (2) Hydrophobic; and (3) Moisture Management (MM). Wearing these garments, human subjects ran on treadmill according to a pre-designed experimental protocol. It was found that during exercise hydrophilic cotton caused significantly higher mean skin temperature than MM and hydrophobic cotton fabrics, while during recovery, hydrophilic and MM cotton fabrics caused significantly higher mean skin temperature than hydrophobic cotton fabric. Hydrophilic cotton fabric caused significantly lower heart rate than MM cotton fabric, lower systolic blood pressure than MM and hydrophobic cotton fabrics. Hydrophobic cotton fabric caused significantly higher urinary catecholamine volume than hydrophilic and MM cotton fabric, indicating stronger physical stress. Hydrophilic cotton fabric caused significantly stronger thermal and humidity sensations than MM and hydrophobic cotton fabrics at the end of first and second exercise sessions. Hydrophilic cotton fabric caused significantly stronger discomfort sensation than hydrophobic cotton fabric at the end of first session of exercise. In the end of wear trial, MM cotton fabric caused significantly higher tiredness sensation than hydrophilic and hydrophobic cotton fabrics.展开更多
The human gene ATP 13A2 has been proposed to code for an ATP powered ion transporter of the PsB subfamily. Mutations of the human gene ATP1 3A2 were found to underlie an autosomal recessive form of early-onset parkins...The human gene ATP 13A2 has been proposed to code for an ATP powered ion transporter of the PsB subfamily. Mutations of the human gene ATP1 3A2 were found to underlie an autosomal recessive form of early-onset parkinsonism （PD） with pyramidal degeneration and dementia. The ion transported by the ATP13A2 pump is not known, but several studies have shown that the Ps-ATPases influence the homeostasis of intracellular Ca2＋, and thus it has been suggested that they transport Ca2＋. In order to evaluate this possibility Chinese hamster ovary （CHO） cells stably expressing the human ATP13A2 protein have been obtained and the Ca2＋ transport activity of ATP 13A2 was assessed by measuring the ATP-dependent uptake of Ca2＋ into microsomal vesicles. As a positive control vesicles containing the human plasma membrane Ca2＋ pump （PMCA） were used. No significant differences were found between vesicles containing the ATP 13A2 protein and the control. Moreover, Ca2＋ was unable to induce the formation of the P-ATPase acylphosphate intermediate in vesicles containing the expressed ATPl3A2. These results favor the idea that the ATPI3A2 does not transport Ca2＋.展开更多
Water-sediment regulation of the Yellow River is to regulate and control the flow and sediment transport relationship of the lower reaches through reservoirs on the main streams and tributaries to create balance betwe...Water-sediment regulation of the Yellow River is to regulate and control the flow and sediment transport relationship of the lower reaches through reservoirs on the main streams and tributaries to create balance between water and sediment so that sediment transport capacity of the downstream channels can be maximized,shrinking of channels be contained,and medium flood channel be restored and maintained.Many years' research by the Yellow River Conservancy Commission(YRCC) reveals the water and sediment transport relationship that will prevent sedimentation at the downstream river channels.Based on this relationship and coming sediment and water conditions in the Yellow River basin,the YRCC,with maximized use of reservoirs on the main streams and tributaries,has developed three models of water-sediment regulation:single Xiaolangdi Reservoir-dominated regulation,space scale water-sediment match,and mainstream reservoirs joint operation.Ten water-sediment regulations based on these three models have resulted in an average drop of 1.5 m in the main channel of the downstream 800 km river and an increase of carrying capacity from 1800 to 4000 m3/s.Besides,the wetland ecosystems of estuarine delta has also been improved and restored significantly.展开更多
基金TheCultureExchangeProgrambetweenChinaandCzechGovernments (No .199899)
文摘A conveyor linear system assumption is based on an approximate description of belt mechanics behavior and constant elastic moduli. It produces analysis errors and improper dynamics simulation in large conveyors. The belt non-linear characteristics based on sag are described and the belt equivalent elastic moduli expression is deduced. The relationship between belt-equivalent elastic module and elastic module is studied, and their ratio varies from 0.1 to 1.0. The non-linear motion equation with a lumped element model is put forward. Its increment equation and numerical solution are built. A dynamics simulation on a conveyor is carried out, mainly to calculate and compare belt speed, acceleration, tension, displacement of gravity take-up and wave period with linear and non-linear models. It shows that the simulation errors between two models vary from 6% to 50%.
基金The Research Committee of Hong Kong Polytechnic University(No.G-YD56,A188,A174)
文摘We investigated the influences of liquid water transfer property of cotton fabric on human physiological responses, such as ear canal temperature, heart rate, blood pressure, stress hormone, during exercise and recovery. Long sleeves cotton knitted sportswear treated to have special liquid water transfer property were prepared: (1) Hydrophilic; (2) Hydrophobic; and (3) Moisture Management (MM). Wearing these garments, human subjects ran on treadmill according to a pre-designed experimental protocol. It was found that during exercise hydrophilic cotton caused significantly higher mean skin temperature than MM and hydrophobic cotton fabrics, while during recovery, hydrophilic and MM cotton fabrics caused significantly higher mean skin temperature than hydrophobic cotton fabric. Hydrophilic cotton fabric caused significantly lower heart rate than MM cotton fabric, lower systolic blood pressure than MM and hydrophobic cotton fabrics. Hydrophobic cotton fabric caused significantly higher urinary catecholamine volume than hydrophilic and MM cotton fabric, indicating stronger physical stress. Hydrophilic cotton fabric caused significantly stronger thermal and humidity sensations than MM and hydrophobic cotton fabrics at the end of first and second exercise sessions. Hydrophilic cotton fabric caused significantly stronger discomfort sensation than hydrophobic cotton fabric at the end of first session of exercise. In the end of wear trial, MM cotton fabric caused significantly higher tiredness sensation than hydrophilic and hydrophobic cotton fabrics.
文摘The human gene ATP 13A2 has been proposed to code for an ATP powered ion transporter of the PsB subfamily. Mutations of the human gene ATP1 3A2 were found to underlie an autosomal recessive form of early-onset parkinsonism （PD） with pyramidal degeneration and dementia. The ion transported by the ATP13A2 pump is not known, but several studies have shown that the Ps-ATPases influence the homeostasis of intracellular Ca2＋, and thus it has been suggested that they transport Ca2＋. In order to evaluate this possibility Chinese hamster ovary （CHO） cells stably expressing the human ATP13A2 protein have been obtained and the Ca2＋ transport activity of ATP 13A2 was assessed by measuring the ATP-dependent uptake of Ca2＋ into microsomal vesicles. As a positive control vesicles containing the human plasma membrane Ca2＋ pump （PMCA） were used. No significant differences were found between vesicles containing the ATP 13A2 protein and the control. Moreover, Ca2＋ was unable to induce the formation of the P-ATPase acylphosphate intermediate in vesicles containing the expressed ATPl3A2. These results favor the idea that the ATPI3A2 does not transport Ca2＋.
文摘Water-sediment regulation of the Yellow River is to regulate and control the flow and sediment transport relationship of the lower reaches through reservoirs on the main streams and tributaries to create balance between water and sediment so that sediment transport capacity of the downstream channels can be maximized,shrinking of channels be contained,and medium flood channel be restored and maintained.Many years' research by the Yellow River Conservancy Commission(YRCC) reveals the water and sediment transport relationship that will prevent sedimentation at the downstream river channels.Based on this relationship and coming sediment and water conditions in the Yellow River basin,the YRCC,with maximized use of reservoirs on the main streams and tributaries,has developed three models of water-sediment regulation:single Xiaolangdi Reservoir-dominated regulation,space scale water-sediment match,and mainstream reservoirs joint operation.Ten water-sediment regulations based on these three models have resulted in an average drop of 1.5 m in the main channel of the downstream 800 km river and an increase of carrying capacity from 1800 to 4000 m3/s.Besides,the wetland ecosystems of estuarine delta has also been improved and restored significantly.
