Based on heterogeneous and porous medium seepage of air leakage-diffusion equation, as well as, gas and porous medium synthesis heat transferring equation, a spontaneous combustion non-steady numerical model of nitrog...Based on heterogeneous and porous medium seepage of air leakage-diffusion equation, as well as, gas and porous medium synthesis heat transferring equation, a spontaneous combustion non-steady numerical model of nitrogen injection goaf was established, which can be solved by upwind finite element numerical simulation method si- multaneously. Taking the working face for example; air leakage seepage, nitrogen flow and gas distribution can be described in visual display in nitrogen injection goaf and the oxygen （O2）, carbon monoxide （CO） concentration and temperature distribution, as well as, their change were described in theory during the coal left behind combustion in goaf, which above reveals the complex mechanics course （mechanism） of seepage, diffusion and oxidation heat releasing during coal spontaneous combustion and its restraining. During the calculation, the effect factors of gas springing out and working face advancing were considered fully, and the spontaneous combustion course under different amount of nitrogen injection was simulated. The conclusions were obtained that under nitrogen injection condition, the high spontaneous combustion temperature area lean to the inlet air, but the shape becomes narrower, with the amount of nitrogen rising, the spontaneous combustion period becomes longer till to it does not happen. Meanwhile the nitrogen injection accelerates gas springing out in goaf. The result that turns out in theory simulation fits to practical nitrogen injection.展开更多
目的探究胸腔镜下自体血经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)导管瘘口注射封堵术在难治性气胸患者中的应用效果与安全性。方法选取2015年3月至2017年11月宁波市第七医院的72例难治性气胸患者为研...目的探究胸腔镜下自体血经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)导管瘘口注射封堵术在难治性气胸患者中的应用效果与安全性。方法选取2015年3月至2017年11月宁波市第七医院的72例难治性气胸患者为研究对象,将其根据治疗方式的不同分为对照组(高渗葡萄糖胸膜固定术组)36例和观察组(胸腔镜下自体血经PICC导管瘘口注射封堵术组)36例。比较两组的临床治疗效果、不良反应发生率、不同时间的复发率、治疗前后的气促分级、血气分析结果及应激相关指标。结果观察组的总有效率为97.22%,高于对照组的80.56%(χ~2=5.063,P=0.024),不良反应发生率为11.11%低于对照组的44.44%(χ~2=9.969,P=0.001),治疗后3、6、12个月的复发率分别为0%、0%及2.78%,低于对照组的11.11%、13.89%及16.67%(χ~2=4.235、5.373、3.956,P=0.039、0.020、0.046),治疗后的气促分级、血气分析结果及应激相关指标均优于对照组,差异有统计学意义(P均<0.05)。结论胸腔镜下自体血经PICC导管瘘口注射封堵术在难治性气胸患者中的应用效果较好,安全性也较高,在难治性气胸患者中的应用价值较高。展开更多
文摘Based on heterogeneous and porous medium seepage of air leakage-diffusion equation, as well as, gas and porous medium synthesis heat transferring equation, a spontaneous combustion non-steady numerical model of nitrogen injection goaf was established, which can be solved by upwind finite element numerical simulation method si- multaneously. Taking the working face for example; air leakage seepage, nitrogen flow and gas distribution can be described in visual display in nitrogen injection goaf and the oxygen （O2）, carbon monoxide （CO） concentration and temperature distribution, as well as, their change were described in theory during the coal left behind combustion in goaf, which above reveals the complex mechanics course （mechanism） of seepage, diffusion and oxidation heat releasing during coal spontaneous combustion and its restraining. During the calculation, the effect factors of gas springing out and working face advancing were considered fully, and the spontaneous combustion course under different amount of nitrogen injection was simulated. The conclusions were obtained that under nitrogen injection condition, the high spontaneous combustion temperature area lean to the inlet air, but the shape becomes narrower, with the amount of nitrogen rising, the spontaneous combustion period becomes longer till to it does not happen. Meanwhile the nitrogen injection accelerates gas springing out in goaf. The result that turns out in theory simulation fits to practical nitrogen injection.
文摘目的探究胸腔镜下自体血经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)导管瘘口注射封堵术在难治性气胸患者中的应用效果与安全性。方法选取2015年3月至2017年11月宁波市第七医院的72例难治性气胸患者为研究对象,将其根据治疗方式的不同分为对照组(高渗葡萄糖胸膜固定术组)36例和观察组(胸腔镜下自体血经PICC导管瘘口注射封堵术组)36例。比较两组的临床治疗效果、不良反应发生率、不同时间的复发率、治疗前后的气促分级、血气分析结果及应激相关指标。结果观察组的总有效率为97.22%,高于对照组的80.56%(χ~2=5.063,P=0.024),不良反应发生率为11.11%低于对照组的44.44%(χ~2=9.969,P=0.001),治疗后3、6、12个月的复发率分别为0%、0%及2.78%,低于对照组的11.11%、13.89%及16.67%(χ~2=4.235、5.373、3.956,P=0.039、0.020、0.046),治疗后的气促分级、血气分析结果及应激相关指标均优于对照组,差异有统计学意义(P均<0.05)。结论胸腔镜下自体血经PICC导管瘘口注射封堵术在难治性气胸患者中的应用效果较好,安全性也较高,在难治性气胸患者中的应用价值较高。
