The careers of three Chinese physicists,Hu Ning,Ma Shijun,and Peng Huanwu at the Dublin Institute for Advance Studies in the 1940s,and later,are described.A brief history of the foundation and operations of the instit...The careers of three Chinese physicists,Hu Ning,Ma Shijun,and Peng Huanwu at the Dublin Institute for Advance Studies in the 1940s,and later,are described.A brief history of the foundation and operations of the institute,as well as the roles in it of Erwin Schrodinger,Walter Heitler,Max Born,and others are included.Some details are given of the works carried out there.The three men's post-institute careers are described,Ma eventually in Australia,and Hu and Peng in the People's Republic of China where they became distinguished leaders of theoretical physics research.展开更多
The corrugated packing is prone to break down easily, which can affect the tower efficiency substantially. It is the inner environment of the vacuum distillation tower including the temperature and chemical nature of ...The corrugated packing is prone to break down easily, which can affect the tower efficiency substantially. It is the inner environment of the vacuum distillation tower including the temperature and chemical nature of fluid that lead to the packing damage. The theoretical analysis indicates that it is the inner material flow of vacuum distillation tower that leads to the vibration of packing, which can affect the corrosion fatigue of packing significantly. Meanwhile, the modal shape and inherent frequency of packing under prestress can be obtained by means of mathematical analysis. Based on the two kinds of analysis, the flow induced vibration and corrosion fatigue are accountable for the failure of packing.展开更多
The methane drainage can not only make coal seams deformation, but also effect its stress distribution. Based on lab experiment on methane drainage with a cubic coal sample of 500 mm×500 mm×500 mm, mutative ...The methane drainage can not only make coal seams deformation, but also effect its stress distribution. Based on lab experiment on methane drainage with a cubic coal sample of 500 mm×500 mm×500 mm, mutative law of coal of pore pressure (p) and effective stress (σef)i were investigated during methane drainage with the coal sample of China Lu'an coal field No.3 coal seam. The experiment results indicate: during methane drainage pore pressure (p) follows exponential attenuation law: p=aexp(-bt); effective stress (σef)i of coal masses follows logarithm incremental law: (σef),=aln t+b, (i=x, y, z); effective stress coefficient(a) follows logarithm attenuation law: a=a-bln t; effective stress coefficient, volume stress (Θef) and pore pressure (p) follow bilinear law.展开更多
Risk management in Botswana has been very ineffective at assisting projects to be on time, on budget, and meeting client's/buyer's expectations. Traditional risk management attempts to manage, control, and direct a ...Risk management in Botswana has been very ineffective at assisting projects to be on time, on budget, and meeting client's/buyer's expectations. Traditional risk management attempts to manage, control, and direct a project through various phases, from planning and design, through procurement, and to construction. However, the risk management in Botswana seems to be either not implemented or not successful. The project performance in Botswana has a poor performance record. The researchers are attempting to identify why the traditional project/risk management is not working. In analyzing the problem in Botswana, the researchers discovered that the traditional risk management model was theoretically unsound, and designed a new project and risk model, with an entirely different approach to risk. The new model is an outgrowth of the highly successful Performance Information Procurement System (PIPS) and the Information Measurement Theory (IMT)/Kashiwagi Solution Model (KSM) concepts. The approach has been presented to some Botswana clients and academics and has received a favorable response. The development of the new risk model will lead to a huge change in the paradigm for delivering projects in Botswana. The theoretical development of the new risk model is ongoing at the University of Botswana as a part of a doctoral dissertation.展开更多
文摘The careers of three Chinese physicists,Hu Ning,Ma Shijun,and Peng Huanwu at the Dublin Institute for Advance Studies in the 1940s,and later,are described.A brief history of the foundation and operations of the institute,as well as the roles in it of Erwin Schrodinger,Walter Heitler,Max Born,and others are included.Some details are given of the works carried out there.The three men's post-institute careers are described,Ma eventually in Australia,and Hu and Peng in the People's Republic of China where they became distinguished leaders of theoretical physics research.
文摘The corrugated packing is prone to break down easily, which can affect the tower efficiency substantially. It is the inner environment of the vacuum distillation tower including the temperature and chemical nature of fluid that lead to the packing damage. The theoretical analysis indicates that it is the inner material flow of vacuum distillation tower that leads to the vibration of packing, which can affect the corrosion fatigue of packing significantly. Meanwhile, the modal shape and inherent frequency of packing under prestress can be obtained by means of mathematical analysis. Based on the two kinds of analysis, the flow induced vibration and corrosion fatigue are accountable for the failure of packing.
基金Supported by the National Natural Science Foundation of China(50404017) the Natural Science Foundation for Young Scientists of Shanxi Province, China (20051026)
文摘The methane drainage can not only make coal seams deformation, but also effect its stress distribution. Based on lab experiment on methane drainage with a cubic coal sample of 500 mm×500 mm×500 mm, mutative law of coal of pore pressure (p) and effective stress (σef)i were investigated during methane drainage with the coal sample of China Lu'an coal field No.3 coal seam. The experiment results indicate: during methane drainage pore pressure (p) follows exponential attenuation law: p=aexp(-bt); effective stress (σef)i of coal masses follows logarithm incremental law: (σef),=aln t+b, (i=x, y, z); effective stress coefficient(a) follows logarithm attenuation law: a=a-bln t; effective stress coefficient, volume stress (Θef) and pore pressure (p) follow bilinear law.
文摘Risk management in Botswana has been very ineffective at assisting projects to be on time, on budget, and meeting client's/buyer's expectations. Traditional risk management attempts to manage, control, and direct a project through various phases, from planning and design, through procurement, and to construction. However, the risk management in Botswana seems to be either not implemented or not successful. The project performance in Botswana has a poor performance record. The researchers are attempting to identify why the traditional project/risk management is not working. In analyzing the problem in Botswana, the researchers discovered that the traditional risk management model was theoretically unsound, and designed a new project and risk model, with an entirely different approach to risk. The new model is an outgrowth of the highly successful Performance Information Procurement System (PIPS) and the Information Measurement Theory (IMT)/Kashiwagi Solution Model (KSM) concepts. The approach has been presented to some Botswana clients and academics and has received a favorable response. The development of the new risk model will lead to a huge change in the paradigm for delivering projects in Botswana. The theoretical development of the new risk model is ongoing at the University of Botswana as a part of a doctoral dissertation.