We investigate the evolution of cooperation with evolutionary public goods games based on finite populations, where four pure strategies： cooperators, defectors, punishers and loners who are unwilling to participate ...We investigate the evolution of cooperation with evolutionary public goods games based on finite populations, where four pure strategies： cooperators, defectors, punishers and loners who are unwilling to participate are considered. By adopting approximate best response dynamics, we show that the magnitude of rationality not only quantitatively explains the experiment results in [Nature （London） 425 （2003） 390], but also it will heavily influence the evolution of cooperation. Compared with previous results of infinite populations, which result in two equilibriums, we show that there merely exists a special equilibrium cooperation. In addition, we characterize that loner＇s and the relevant high value of bounded rationality will sustain payoff plays an active role in the maintenance of cooperation, which will only be warranted for the low and moderate values of loner＇s payoff. It thus indicates the effects of rationality and loner＇s payoff will influence the cooperation. Finally, we highlight the important result that the introduction of voluntary participation and punishment will facilitate cooperation greatly.展开更多
Climate protection is a problem of sustaining a public resource. All countries of the world should take action to deal with climate change. However, such an action is actually a game process where each country chooses...Climate protection is a problem of sustaining a public resource. All countries of the world should take action to deal with climate change. However, such an action is actually a game process where each country chooses to cooperate or defect under constrained condition. Here we study the group behavior of countries in dealing with climate change. In our study, the countries of the world are considered as players who are distributed on an assumed spatial network. A new evolution rule is proposed to model the game process among the players. Our extensive experiments demonstrate that under constrained condition, the local psychology of players possibly results in the formation of local group. Some local and global oscillations can be found where part or all of the players change their choices periodically.展开更多
The practice of ventilation is continually evolving with new technological advances developed in the mining industry.In recent years the advances in diesel engine technologies,ventilation modeling software,and ventila...The practice of ventilation is continually evolving with new technological advances developed in the mining industry.In recent years the advances in diesel engine technologies,ventilation modeling software,and ventilation management capacities have redefined the historical methods used to evaluate systems.The advances re-evaluate previous methods used to calculate the airflow requirements for the dilution of diesel exhaust fumes.Modeling software has become an integral part of planning and developing ventilation systems in partnership with graphical mine design software packages to generate realistic representations of the mine.Significant advances in ventilation control strategies through remote sensors and monitoring capabilities have been developed to results in cost savings.Though there has been much advancement in mine ventilation technology,the practices and basic ventilation principals enacted through the ventilation engineer cannot be placated with technological advances only.展开更多
The extruded protoplasm from the coenocytic green alga,Bryopsis hypnoides Lamouroux,was able to reform a cell wall and develop further into a mature alga in seawater.In this paper,the influence of albumen on the abili...The extruded protoplasm from the coenocytic green alga,Bryopsis hypnoides Lamouroux,was able to reform a cell wall and develop further into a mature alga in seawater.In this paper,the influence of albumen on the ability of aggregation and on the photosynthesis of protoplasm was examined.Results show that the protoplasm of B.hypnoides could aggregate in either albumen or chicken egg,which is similar to that in seawater.However unlike in seawater,the aggregation from B.hypnoides in albumen and chicken egg failed to develop into a mature individual.Interestingly,the protoplasm of B.hypnoides could maintain its photosynthetic O_2 evolution in albumen and chicken egg,while the time in chicken egg was longer than that in albumen.展开更多
At the end of 2015, the United States lifted a 40-year ban on crude oil exports, which has far-reaching implications for the global crude oil market and crude oil trade patterns. Since the release of crude oil exports...At the end of 2015, the United States lifted a 40-year ban on crude oil exports, which has far-reaching implications for the global crude oil market and crude oil trade patterns. Since the release of crude oil exports, with the recovery of crude oil production and improved export infrastructure in the United States, U.S. crude oil exports have been growing rapidly, with an average of about one million barrels/day in 2017, making the U.S one of the major global crude oil exporters. Currently, the AsiaPacific region has replaced North America as the first major destination for U.S. crude oil exports. In light of future trends in the oil refining industry of the Asia-Pacific region, it will usher in a new wave of refinery operations around 2020 and crude oil imports will continue to grow rapidly. The American region, represented by the United States, will replace West Africa as the second largest source of crude oil imports to the Asia-Pacific region, and that energy trade cooperation between the Asia-Pacific region and the United States will continue to grow. In particular, for China, the United States will become an important source of crude oil imports for our country in the future, and the two countries will shift from the past of energy competition to energy cooperation. Sino-US energy trade will play a more active role in economic and trade cooperation between the two countries.展开更多
基金Supported by National Nature Science Foundation under Grant No.60904063the Tianjin municipal Natural Science Foundation under Grant Nos.11JCYBJC06600,11ZCKF6X00900,11ZCKFGX00900
文摘We investigate the evolution of cooperation with evolutionary public goods games based on finite populations, where four pure strategies： cooperators, defectors, punishers and loners who are unwilling to participate are considered. By adopting approximate best response dynamics, we show that the magnitude of rationality not only quantitatively explains the experiment results in [Nature （London） 425 （2003） 390], but also it will heavily influence the evolution of cooperation. Compared with previous results of infinite populations, which result in two equilibriums, we show that there merely exists a special equilibrium cooperation. In addition, we characterize that loner＇s and the relevant high value of bounded rationality will sustain payoff plays an active role in the maintenance of cooperation, which will only be warranted for the low and moderate values of loner＇s payoff. It thus indicates the effects of rationality and loner＇s payoff will influence the cooperation. Finally, we highlight the important result that the introduction of voluntary participation and punishment will facilitate cooperation greatly.
基金Supported by the State Key Laboratory of Rail Traffic Control and Safety under Grant Nos.RCS2008ZZ001 and RCS2010ZZ001,Beijing Jiaotong University
文摘Climate protection is a problem of sustaining a public resource. All countries of the world should take action to deal with climate change. However, such an action is actually a game process where each country chooses to cooperate or defect under constrained condition. Here we study the group behavior of countries in dealing with climate change. In our study, the countries of the world are considered as players who are distributed on an assumed spatial network. A new evolution rule is proposed to model the game process among the players. Our extensive experiments demonstrate that under constrained condition, the local psychology of players possibly results in the formation of local group. Some local and global oscillations can be found where part or all of the players change their choices periodically.
文摘The practice of ventilation is continually evolving with new technological advances developed in the mining industry.In recent years the advances in diesel engine technologies,ventilation modeling software,and ventilation management capacities have redefined the historical methods used to evaluate systems.The advances re-evaluate previous methods used to calculate the airflow requirements for the dilution of diesel exhaust fumes.Modeling software has become an integral part of planning and developing ventilation systems in partnership with graphical mine design software packages to generate realistic representations of the mine.Significant advances in ventilation control strategies through remote sensors and monitoring capabilities have been developed to results in cost savings.Though there has been much advancement in mine ventilation technology,the practices and basic ventilation principals enacted through the ventilation engineer cannot be placated with technological advances only.
基金Supported by the National Natural Science Foundation of China (No.30830015)the Project of Supporting the National Development (No.2006BAD09A04)and the National High Technology and Development Program of China (863 Program) (Nos.2006AA 10A402,2007AA09Z406,2006AA05Z112,2006AA10A413)
文摘The extruded protoplasm from the coenocytic green alga,Bryopsis hypnoides Lamouroux,was able to reform a cell wall and develop further into a mature alga in seawater.In this paper,the influence of albumen on the ability of aggregation and on the photosynthesis of protoplasm was examined.Results show that the protoplasm of B.hypnoides could aggregate in either albumen or chicken egg,which is similar to that in seawater.However unlike in seawater,the aggregation from B.hypnoides in albumen and chicken egg failed to develop into a mature individual.Interestingly,the protoplasm of B.hypnoides could maintain its photosynthetic O_2 evolution in albumen and chicken egg,while the time in chicken egg was longer than that in albumen.
文摘At the end of 2015, the United States lifted a 40-year ban on crude oil exports, which has far-reaching implications for the global crude oil market and crude oil trade patterns. Since the release of crude oil exports, with the recovery of crude oil production and improved export infrastructure in the United States, U.S. crude oil exports have been growing rapidly, with an average of about one million barrels/day in 2017, making the U.S one of the major global crude oil exporters. Currently, the AsiaPacific region has replaced North America as the first major destination for U.S. crude oil exports. In light of future trends in the oil refining industry of the Asia-Pacific region, it will usher in a new wave of refinery operations around 2020 and crude oil imports will continue to grow rapidly. The American region, represented by the United States, will replace West Africa as the second largest source of crude oil imports to the Asia-Pacific region, and that energy trade cooperation between the Asia-Pacific region and the United States will continue to grow. In particular, for China, the United States will become an important source of crude oil imports for our country in the future, and the two countries will shift from the past of energy competition to energy cooperation. Sino-US energy trade will play a more active role in economic and trade cooperation between the two countries.
