Gas hydrates are solid inclusion compounds that are composed of a three-dimensional hydrogen-bonded network of water cages that can trap small gas molecules, such as methane and carbon dioxide. Understanding the rheol...Gas hydrates are solid inclusion compounds that are composed of a three-dimensional hydrogen-bonded network of water cages that can trap small gas molecules, such as methane and carbon dioxide. Understanding the rheological properties of gas hydrate crystals in solution can he critical in a number of energy applications, including the transportation of natural gas in suhsea and onshore operations, as well as technological applications for gas separation, desalination, or sequestration. A number of exper- imental and modeling studies have been done on hydrate slurry rheology; however, the link between theory and experiment is not well-defined. This article provides a review on the current state of the art of hydrate slurry viscosity measurements from high- and low-pressure rheometer studies and high-pressure flowloops over a range of different sub-cooling （ATsub = TequiI Texp） and fluid conditions, including for water and oil continuous systems. The theoretical models that have been developed to describe the gas hydrate slurry relative viscosity are also reviewed. Perspectives＇ linkage between the experiments and theory is also discussed.展开更多
The ＂new normal＂ is the current stage of development of China＇s economy. The ＂new＂ in new normal means different to past; the ＂normal＂ means relatively stable. For a period of time in the future, the decrease o...The ＂new normal＂ is the current stage of development of China＇s economy. The ＂new＂ in new normal means different to past; the ＂normal＂ means relatively stable. For a period of time in the future, the decrease of potential growth rate has become an indisputable fact. Social security fund is an important source of funds for the protection of people＇s livelihood, whose every movement often attract much attention. Under the situation of new normal economy, how to ensure the preserving or increasing value of social security funds on the premise of security is the core task in the operations management of social security fund investment. At present, there are some difficulties in the development of the social security funds, such as the management system and operation mechanism are not perfect, some institutional measures have not been fully implemented and the progress of the law and regulations is slow. In this paper, we will put forward some corresponding improvement measures, such as expand the scope of social security fund investment, accelerate the implementation of the nominal account system and strengthen the actuarial management of social security fund.展开更多
文摘Gas hydrates are solid inclusion compounds that are composed of a three-dimensional hydrogen-bonded network of water cages that can trap small gas molecules, such as methane and carbon dioxide. Understanding the rheological properties of gas hydrate crystals in solution can he critical in a number of energy applications, including the transportation of natural gas in suhsea and onshore operations, as well as technological applications for gas separation, desalination, or sequestration. A number of exper- imental and modeling studies have been done on hydrate slurry rheology; however, the link between theory and experiment is not well-defined. This article provides a review on the current state of the art of hydrate slurry viscosity measurements from high- and low-pressure rheometer studies and high-pressure flowloops over a range of different sub-cooling （ATsub = TequiI Texp） and fluid conditions, including for water and oil continuous systems. The theoretical models that have been developed to describe the gas hydrate slurry relative viscosity are also reviewed. Perspectives＇ linkage between the experiments and theory is also discussed.
文摘The ＂new normal＂ is the current stage of development of China＇s economy. The ＂new＂ in new normal means different to past; the ＂normal＂ means relatively stable. For a period of time in the future, the decrease of potential growth rate has become an indisputable fact. Social security fund is an important source of funds for the protection of people＇s livelihood, whose every movement often attract much attention. Under the situation of new normal economy, how to ensure the preserving or increasing value of social security funds on the premise of security is the core task in the operations management of social security fund investment. At present, there are some difficulties in the development of the social security funds, such as the management system and operation mechanism are not perfect, some institutional measures have not been fully implemented and the progress of the law and regulations is slow. In this paper, we will put forward some corresponding improvement measures, such as expand the scope of social security fund investment, accelerate the implementation of the nominal account system and strengthen the actuarial management of social security fund.
