I^2C总线是Inter IC BUS的简称，它是Philips公司研制出来的串行扩展技术。I^2C总线的意思是“完成集成功能单元之间信息交换的规范或协议”。目前，国内生产的彩色电视机大都采用了具有I^2C总线的机芯，不仅增加了电视机的可靠性，同...I^2C总线是Inter IC BUS的简称，它是Philips公司研制出来的串行扩展技术。I^2C总线的意思是“完成集成功能单元之间信息交换的规范或协议”。目前，国内生产的彩色电视机大都采用了具有I^2C总线的机芯，不仅增加了电视机的可靠性，同时也为自动化的调试提供了可能，大大提高生产效率。具有自检功能使得整机的故障诊断与跟踪，调试和维修都十分方便。展开更多
The use of sulfur hexafiuoride （SF6） as a tracer gas for analyzing underground mine ventilation systems has been practiced for over 30 years. As a result, the methods used to release, sample, and analyze SF6 are wel...The use of sulfur hexafiuoride （SF6） as a tracer gas for analyzing underground mine ventilation systems has been practiced for over 30 years. As a result, the methods used to release, sample, and analyze SF6 are well accepted. As the complexity and size of underground mine ventilation networks increase, the ability of a SF6 to function as a convenient and rapid means of analysis diminishes. The utilization of multiple tracer gases can mitigate this by removing the need to purge the background presence of a tracer before conducting another release and allowing for a more comprehensive evaluation using multi-zone tech- niques. Recent studies have identified perfluoromethylcyclohexane （PMCH） as a possible supplement for SF6 in underground mine ventilation tracer studies. However, the deployment of PMCH remains a challenge because of this compounds physical properties. This paper evaluates a PMCH permeation plug release vessel （PPRV） under controlled turbulent conditions. The details of the experimental parameters used in the evaluation as well as a discussion regarding the performance of the PPRV are included.展开更多
This paper describes the design of four types of swirlers which produce different velocity profiles.The data of confined turbulent swirling flowfields are obtained from experiments and numerical calculations.The actua...This paper describes the design of four types of swirlers which produce different velocity profiles.The data of confined turbulent swirling flowfields are obtained from experiments and numerical calculations.The actual flow profiles at the swirler exit basically agree with the desired profiles. Two kinds of turbulence models,k-ε model and DDC model,are used to predict the flowfields produced by swirl augmentors.The results show that the DDC model,based on interaction between dissipation and dispersion,can overcome the defect of k-ε model and predict the swirling flowfields more accurately than k-ε model.展开更多
文摘I^2C总线是Inter IC BUS的简称，它是Philips公司研制出来的串行扩展技术。I^2C总线的意思是“完成集成功能单元之间信息交换的规范或协议”。目前，国内生产的彩色电视机大都采用了具有I^2C总线的机芯，不仅增加了电视机的可靠性，同时也为自动化的调试提供了可能，大大提高生产效率。具有自检功能使得整机的故障诊断与跟踪，调试和维修都十分方便。
文摘The use of sulfur hexafiuoride （SF6） as a tracer gas for analyzing underground mine ventilation systems has been practiced for over 30 years. As a result, the methods used to release, sample, and analyze SF6 are well accepted. As the complexity and size of underground mine ventilation networks increase, the ability of a SF6 to function as a convenient and rapid means of analysis diminishes. The utilization of multiple tracer gases can mitigate this by removing the need to purge the background presence of a tracer before conducting another release and allowing for a more comprehensive evaluation using multi-zone tech- niques. Recent studies have identified perfluoromethylcyclohexane （PMCH） as a possible supplement for SF6 in underground mine ventilation tracer studies. However, the deployment of PMCH remains a challenge because of this compounds physical properties. This paper evaluates a PMCH permeation plug release vessel （PPRV） under controlled turbulent conditions. The details of the experimental parameters used in the evaluation as well as a discussion regarding the performance of the PPRV are included.
文摘This paper describes the design of four types of swirlers which produce different velocity profiles.The data of confined turbulent swirling flowfields are obtained from experiments and numerical calculations.The actual flow profiles at the swirler exit basically agree with the desired profiles. Two kinds of turbulence models,k-ε model and DDC model,are used to predict the flowfields produced by swirl augmentors.The results show that the DDC model,based on interaction between dissipation and dispersion,can overcome the defect of k-ε model and predict the swirling flowfields more accurately than k-ε model.
