In this paper, the concept of type 2 expressions (2Es for short) is briefly introduced, and it is proved strictly that CFL class is precisely the language class expressed by 2Es. A new proof using 2Es to pumping lemma...In this paper, the concept of type 2 expressions (2Es for short) is briefly introduced, and it is proved strictly that CFL class is precisely the language class expressed by 2Es. A new proof using 2Es to pumping lemma for CFLs is geven.展开更多
The application and fundamental study on turbulent premixed combustion of hydrogen enriched natural gas is reviewed in this paper.Discussions include the combustion characteristics of direct injection engine fueled wi...The application and fundamental study on turbulent premixed combustion of hydrogen enriched natural gas is reviewed in this paper.Discussions include the combustion characteristics of direct injection engine fueled with hydrogen enriched natural gas,visualization study of direct injection combustion of hydrogen enriched natural gas using a constant volume vessel,and the fundamental study of turbulent premixed combustion of hydrogen enriched natural gas.The effect of additional hydrogen on the combustion process of natural gas engine is investigated from the fundamental view of the interaction between combustion reaction and turbulent flow.展开更多
From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed ...From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed as a molecule state composed of D 0 0.The contribution of the resonance 0 is the attractive interaction between two heavy mesons in this molecule state.The calculated mass of X is consistent with the experimental data.展开更多
文摘In this paper, the concept of type 2 expressions (2Es for short) is briefly introduced, and it is proved strictly that CFL class is precisely the language class expressed by 2Es. A new proof using 2Es to pumping lemma for CFLs is geven.
基金supported by the National Natural Science Foundation of China(Grant Nos.51376004 and 51006080)the National Basic Research Program of China("973"Program)(Grant No.2013CB228406)
文摘The application and fundamental study on turbulent premixed combustion of hydrogen enriched natural gas is reviewed in this paper.Discussions include the combustion characteristics of direct injection engine fueled with hydrogen enriched natural gas,visualization study of direct injection combustion of hydrogen enriched natural gas using a constant volume vessel,and the fundamental study of turbulent premixed combustion of hydrogen enriched natural gas.The effect of additional hydrogen on the combustion process of natural gas engine is investigated from the fundamental view of the interaction between combustion reaction and turbulent flow.
文摘From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed as a molecule state composed of D 0 0.The contribution of the resonance 0 is the attractive interaction between two heavy mesons in this molecule state.The calculated mass of X is consistent with the experimental data.
