Coal dust is a primary threat to underground coal miners.The most common approach to control coal dust is hydraulic methods,such as water spray and coal seam water injection.To improve the dust suppressant efficiency ...Coal dust is a primary threat to underground coal miners.The most common approach to control coal dust is hydraulic methods,such as water spray and coal seam water injection.To improve the dust suppressant efficiency of hydraulic methods,a novel chemical composite dust suppressant,called NCZ,was prepared in this study using calcium chloride(CaCl_(2)),magnesium chloride(MgCl_(2)),and nonionic surfactants using a thermal synthesis method.The water-retaining properties of NCZ powder and its solutions were characterized using the water absorption rate(WAR)and evaporation rate(ER),respectively,and the wetting abilities of the NCZ solutions on coal dust were tested using the initial contact angle(ICA)and sink rate(SR).The results indicate that the NCZ solutions have anti-evaporation effects,and the ER of the solution with a 20.0 wt%NCZ is reduced by 11.7%compared with that of clean water.Furthermore,NCZ solutions have remarkable enhancement effects on the wettability of coal dust.The ICA and SR of clean water and the NCZ solution at 20.0 wt%are 141.9°and 0 mg/s,and 29.3°and 1.46 mg/s,respectively.Finally,quantitative relationships between the solution surface tension and the ICA and IR were established using the least squares method.This study provides a new product for dust suppression in underground mines,which is significant for the optimum applied con-centration of dust suppressant in mining operations.展开更多
Fluidization under the action of external forces has recently received much attention at home and abroad.Funda-mental study in this novel field has led to the creation of new techniques and equipment in chemical and b...Fluidization under the action of external forces has recently received much attention at home and abroad.Funda-mental study in this novel field has led to the creation of new techniques and equipment in chemical and biochemical pro-cesses,such as reactors for catalytic and pseudo liquid-solid reactions as well as contaetors for gas-liquid-solid systems.In conventional fluidization,solid particles acquire fluidity under the action of a gas or liquid passing at a sufficientvelocity.Under the action of external forces,fluidization can take place at fluid velocities higher than that for particleelutriation or lower than that for incipient fluidization under normal conditions.These external forces can often help toavoid bubbling or suppress backmixing,thus improving mass and heat transfer.Studies on fluidization under various ex-ternal force fields,such as magnetic,oscillating,centrifugal,and ultrasonic,will be reported in a series of papers.展开更多
939152 Determination of urine red blood cellvolume and their distribution curve for identify-ing the source of hematuria by automatic bloodcell counter.LI Shinqiang(李诗强),GUO Duis-han(郭兑山).2nd Affili Hosp,China M...939152 Determination of urine red blood cellvolume and their distribution curve for identify-ing the source of hematuria by automatic bloodcell counter.LI Shinqiang(李诗强),GUO Duis-han(郭兑山).2nd Affili Hosp,China Med U-niv.Chin J Nephrol 1992;8(4):196-198.The paper introduces the determination of urinered blood cells’ volume and their distributioncurve by automatic blood cell counter.Havingobserved the degrees of deformation in shape ofred cells in 106 cases,we found that when theurine red cells’ volume was≤60 fl and theirdistribution curve showed asymmetry,theywere glomerular hematuria,and when it was 】61 f1 and showed symmetry or mixed.展开更多
基金We much appreciate the National Nature Science Foundation of China(Nos.51874015 and 51574017)the National Key Research and Development Program of China(No.2017YFC0805204).
文摘Coal dust is a primary threat to underground coal miners.The most common approach to control coal dust is hydraulic methods,such as water spray and coal seam water injection.To improve the dust suppressant efficiency of hydraulic methods,a novel chemical composite dust suppressant,called NCZ,was prepared in this study using calcium chloride(CaCl_(2)),magnesium chloride(MgCl_(2)),and nonionic surfactants using a thermal synthesis method.The water-retaining properties of NCZ powder and its solutions were characterized using the water absorption rate(WAR)and evaporation rate(ER),respectively,and the wetting abilities of the NCZ solutions on coal dust were tested using the initial contact angle(ICA)and sink rate(SR).The results indicate that the NCZ solutions have anti-evaporation effects,and the ER of the solution with a 20.0 wt%NCZ is reduced by 11.7%compared with that of clean water.Furthermore,NCZ solutions have remarkable enhancement effects on the wettability of coal dust.The ICA and SR of clean water and the NCZ solution at 20.0 wt%are 141.9°and 0 mg/s,and 29.3°and 1.46 mg/s,respectively.Finally,quantitative relationships between the solution surface tension and the ICA and IR were established using the least squares method.This study provides a new product for dust suppression in underground mines,which is significant for the optimum applied con-centration of dust suppressant in mining operations.
文摘Fluidization under the action of external forces has recently received much attention at home and abroad.Funda-mental study in this novel field has led to the creation of new techniques and equipment in chemical and biochemical pro-cesses,such as reactors for catalytic and pseudo liquid-solid reactions as well as contaetors for gas-liquid-solid systems.In conventional fluidization,solid particles acquire fluidity under the action of a gas or liquid passing at a sufficientvelocity.Under the action of external forces,fluidization can take place at fluid velocities higher than that for particleelutriation or lower than that for incipient fluidization under normal conditions.These external forces can often help toavoid bubbling or suppress backmixing,thus improving mass and heat transfer.Studies on fluidization under various ex-ternal force fields,such as magnetic,oscillating,centrifugal,and ultrasonic,will be reported in a series of papers.
文摘939152 Determination of urine red blood cellvolume and their distribution curve for identify-ing the source of hematuria by automatic bloodcell counter.LI Shinqiang(李诗强),GUO Duis-han(郭兑山).2nd Affili Hosp,China Med U-niv.Chin J Nephrol 1992;8(4):196-198.The paper introduces the determination of urinered blood cells’ volume and their distributioncurve by automatic blood cell counter.Havingobserved the degrees of deformation in shape ofred cells in 106 cases,we found that when theurine red cells’ volume was≤60 fl and theirdistribution curve showed asymmetry,theywere glomerular hematuria,and when it was 】61 f1 and showed symmetry or mixed.
