Radial drilling technology, of which the jet bit is the key device, is a research focus in the field of oil drilling and production. This paper establishes mechanical equations for jet bits and analyzes the hydroseal ...Radial drilling technology, of which the jet bit is the key device, is a research focus in the field of oil drilling and production. This paper establishes mechanical equations for jet bits and analyzes the hydroseal of backward jets in bottom holes. Meanwhile this paper establishes a mechanical equation for a high pressure hose and analyzes the axial force distribution. Laboratory experiments indicate that the flow rate, the angle between the backward nozzle axis and the jet bit axis, and the hole diameter are the major influencing factors; the generation of the pulling force is mainly due to the inlet pressure of the jet bit; the backward jets can significantly increase not only the pulling force but also the stability of jet bits. The pulling force would reach 8,376 N under experimental conditions, which can steadily pull the high-pressure hose forward.展开更多
The flow is assumed to be potential, and a boundary integral method is used to solve the Laplace equation for the velocity potential to investigate the shape and the position of the bubble. A 3D code to study the bubb...The flow is assumed to be potential, and a boundary integral method is used to solve the Laplace equation for the velocity potential to investigate the shape and the position of the bubble. A 3D code to study the bubble dynamics is developed, and the calculation results agree well with the experimental data. Numerical analyses are carried out for the interaction between multiple bubbles near the free surface including in-phase and out-of-phase bubbles. The calculation result shows that the bubble period increases with the decrease of the distance between bubble centres because of the depression effect between multiple bubbles. The depression has no relationship with the free surface and it is more apparent for out-of-phase bubbles. There are great differences in dynamic behaviour between the in-phase bubbles and the out-of-phase bubbles due to the depression effect. Furthermore, the interaction among eight bubbles is simulated with a three-dlmensional model, and the evolving process and the relevant physical phenomena are presented. These phenomena can give a reference to the future work on the power of bubbles induced by multiple charges exploding simultaneously or continuously.展开更多
为探讨乳香精油的抗抑郁作用及其可能机制,以慢性轻度不可预见性应激方法建立小鼠抑郁症模型,造模同时每日灌胃给药。用旷场实验、悬尾实验、强迫游泳实验对小鼠进行行为学评测,并用高效液相——电化学方法检测小鼠大脑内5-HT含量。试...为探讨乳香精油的抗抑郁作用及其可能机制,以慢性轻度不可预见性应激方法建立小鼠抑郁症模型,造模同时每日灌胃给药。用旷场实验、悬尾实验、强迫游泳实验对小鼠进行行为学评测,并用高效液相——电化学方法检测小鼠大脑内5-HT含量。试验显示,0.1、0.2 m L/100 g的乳香精油可不同程度地改善小鼠的行为学行为,显著提高小鼠脑内的5-HT含量(P<0.05)。乳香精油具有抗抑郁作用,对中枢单胺类神经递质5-HT的调节是其作用机制之一。展开更多
基金supported by High-tech Research and Development Program of China (No. 2007AA09Z315)Doctoral Foundation of Ministry of Education of China (No. 20070425006)
文摘Radial drilling technology, of which the jet bit is the key device, is a research focus in the field of oil drilling and production. This paper establishes mechanical equations for jet bits and analyzes the hydroseal of backward jets in bottom holes. Meanwhile this paper establishes a mechanical equation for a high pressure hose and analyzes the axial force distribution. Laboratory experiments indicate that the flow rate, the angle between the backward nozzle axis and the jet bit axis, and the hole diameter are the major influencing factors; the generation of the pulling force is mainly due to the inlet pressure of the jet bit; the backward jets can significantly increase not only the pulling force but also the stability of jet bits. The pulling force would reach 8,376 N under experimental conditions, which can steadily pull the high-pressure hose forward.
基金Project supported by the National Natural Science Foundation of China(Grant No50779007)
文摘The flow is assumed to be potential, and a boundary integral method is used to solve the Laplace equation for the velocity potential to investigate the shape and the position of the bubble. A 3D code to study the bubble dynamics is developed, and the calculation results agree well with the experimental data. Numerical analyses are carried out for the interaction between multiple bubbles near the free surface including in-phase and out-of-phase bubbles. The calculation result shows that the bubble period increases with the decrease of the distance between bubble centres because of the depression effect between multiple bubbles. The depression has no relationship with the free surface and it is more apparent for out-of-phase bubbles. There are great differences in dynamic behaviour between the in-phase bubbles and the out-of-phase bubbles due to the depression effect. Furthermore, the interaction among eight bubbles is simulated with a three-dlmensional model, and the evolving process and the relevant physical phenomena are presented. These phenomena can give a reference to the future work on the power of bubbles induced by multiple charges exploding simultaneously or continuously.
文摘为探讨乳香精油的抗抑郁作用及其可能机制,以慢性轻度不可预见性应激方法建立小鼠抑郁症模型,造模同时每日灌胃给药。用旷场实验、悬尾实验、强迫游泳实验对小鼠进行行为学评测,并用高效液相——电化学方法检测小鼠大脑内5-HT含量。试验显示,0.1、0.2 m L/100 g的乳香精油可不同程度地改善小鼠的行为学行为,显著提高小鼠脑内的5-HT含量(P<0.05)。乳香精油具有抗抑郁作用,对中枢单胺类神经递质5-HT的调节是其作用机制之一。
